Showing results for 
Search instead for 
Did you mean: 

Wiring a AC half-bridge with 10mV excitation


I need some assistance getting started.  I need to measure a thermistor with an AC Half Bridge w/ 10 mV excitation, apply a exitation of 2400mV, then take another AC Half Bridge w/10 mV excitation.  I am attempting to wire an anemometer from, which is designed for use with a Campbell datalogger, but I would prefer using LabVIEW.  I don't really know where to start, any help would be greatly appreciated.

0 Kudos
Message 1 of 3
Hello Andrew,

What data acquisition hardware are you using?

I notice that you wanted to ake thermistor measurements and was wondering how to get started with your application. Take a look at the following resources:

Measuring Temperature with an RTD or Thermistor

Working with Thermistors and RTDs

Also take a look at the shipping examples. In LabVIEW click on Help>>Find Examples, then select Hardware Input and Output>>DAQmx>>Analog Measurement>>Temperature

Cont Acq Thermistor Samples-Int   (would be good one to start with for thermistors)

I also took a look that the anemometer device from There isn't enough information about this device. Is there a data sheet? What output are expecting from this device? Will it be a voltage or current? What is the accuracy of the device? Those are all consideration you will have to make.

  Sandra T.

Applications Engineer | National Instruments
0 Kudos
Message 2 of 3
I am using a SCXI  1000 mainframe, SCXI 1200 Aquistion and Control Card, SCXI 1124, and a SCXI 1100.

The instrument information is limited, but this what I gathered from the Campbell program:
Anemomter: A thermistor reading using an AC Half Bridge in the 15mV slow range with voltage excitation at 10 mV.  Also, this instrument requires a excitation of 2400 mV for 5 sec. to heat the sensor befor taking another thermistor reading.

Thermal Conductivity: Requires a thermocouple readings at various intervals (I have this working) during which the sensor is being heated via a Continous Analog Output of 1600 mV.

That is about all the information I can gather, thank you very much for taking the time to help out.

- Andrew
0 Kudos
Message 3 of 3